Separators of this kind are well-known from practice. They generally serve, especially in compressed gas treatment plants built up from various components in particular a cold or adsorption dryer as the main component, by coarse separation of condensate from the compressed gases, to protect the downstream prefilters of the cold or adsorption dryers, against overload due to condensate, “condensate” being understood to mean not only condensed water but also other impurities in the gases such as condensed oil, condensed oil additives, solid particulates etc.
On cost grounds the aim is to use the same housings both for the prefilters and for separators. However this cannot be done that easily because in the case of prefilters, which are regularly equipped with porous filter elements in the form of hollow cylinders, the direction of flow through the filter elements is from inside to outside, while in the case of the separators regularly used as cyclone separators the direction of flow is reversed. This is due to the fact that in the case of cyclone separators the swirl inserts, causing the gases to swirl and flow against the wall of the housing, make a gas inlet pipe necessary in the outer area of the housing. Therefore it is necessary to reverse the gas inlet pipe and gas outlet pipe arranged in the lid relative to those in a prefilter with a porous filter element. In addition cyclone separators have the fundamental disadvantage that their efficiency substantially depends on the volume flow rate of the gases to be dehumidified. In the case of filter housings of different sizes, which have the same diameter but a different length, the same swirl inserts must be fitted in the case of cyclone separators. The longer length therefore cannot be used to increase the efficiency of separation. Also, swirl inserts of different sizes must be used for housings with different diameters.
Furthermore a separator for liquids from liquid-laden gases is well-known from patent literature (DE 196 50 359 A1), wherein the gas is supplied via a gas inlet pipe in the head of the housing and discharged via three chambers, arranged concentrically to each other, in the housing through a gas outlet pipe at the bottom. In order to duct the gas from the central inlet pipe in a radial direction to the outside through the different chambers, a vortex creating element extending over the entire axial length of the chamber is provided in the middle chamber, which forces the gases through radial openings into the middle chamber. Swirling takes place in the middle chamber, which will ensure that liquid separates on the walls of the middle chamber. The gas flowing from the middle chamber through radial openings into the outer chamber is likewise swirled here and is to cause liquid to separate.